Seminoma of the testis: a 22-year experience with radiation therapy.

An analysis is presented of 188 patients with a histological diagnosis of seminoma testis, treated by radical orchiectomy and radiation therapy between 1960 and 1981 at the Cross Cancer Institute. Using the Walter Reed Hospital staging classification, 149 (79%) patients were Stage I, 34 (18%) were Stage II, and 5 (3%) were Stage III. The 5-year survival for all stages was 90%, and for Stage I was 98%, Stage II, 71%, and Stage III, 0%. All were treated primarily with radiation therapy. Prophylactic mediastinal radiation was not employed for Stage I, and was employed in half of Stage II patients. Eleven patients with Stage I relapsed, five in the mediastinum and/or neck nodes. Eight of 11 were cured with further treatment. Stage II patients were subdivided according to the presence or absence of a palpable abdominal mass. Palpable disease (Stage IIB) carried a poorer prognosis. Three of 20 patients without a palpable mass (Stage IIA) died of disease; there was an 82% five-year survival rate. Eight of 14 with a palpable mass (Stage IIB) were cured by radiotherapy; there was a 54% five-year survival rate. All five Stage III patients died within 1 year of diagnosis. Stage I and IIA seminoma is curable by radiation alone. Prophylactic mediastinal radiation is not indicated in either Stage I or IIA disease. Long term toxicity from radiation is not seen. Optimal treatment for Stage IIB disease is undetermined and new treatment regimens should be explored. Stage III disease requires primary chemotherapy.